ASCA observations of deep ROSAT fields — III. The discovery of an obscured Type 2 AGN at z = 0.67 |
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| Authors: | B J Boyle O Almaini I Georgantopoulos A J Blair G C Stewart R E Griffiths T Shanks & K F Gunn |
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| Institution: | Anglo-Australian Observatory, PO Box 296, Epping, NSW 2121, Australia,;Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ,;National Observatory of Athens, Lofos Koufou, Palaia Penteli, 15236 Athens, Greece,;Department of Physics and Astronomy, The University of Leicester, Leicester LE1 7RH,;Department of Physics, Carnegie Mellon University, Wean Hall, 5000 Forbes Ave., Pittsburgh, PA 15213, USA,;Physics Department, University of Durham, South Road, Durham DH1 3LE |
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| Abstract: | We report on the discovery of a narrow-emission-line object at z = 0.672 detected in a deep ASCA survey. The object, AXJ 0341.4–4453, has a flux in the 2–10 keV band of 1.1 ± 0.27 × 10?13 erg s?1 cm?2, corresponding to a luminosity of 1.8 × 1044 erg s?1 ( q 0 = 0.5, H 0 = 50 km s?1 Mpc?1). It is also marginally detected in the ROSAT 0.5–2 keV band with a flux 5.8 × 10?15 erg s?1 cm?2. Both the ASCA data alone and the combined ROSAT/ASCA data show a very hard X-ray spectrum, consistent with either a flat power law (α < 0.1) or photoelectric absorption with a column of n H > 4 × 1022 cm?2 (α = 1). The optical spectrum shows the high-ionization, narrow emission lines typical of a Seyfert 2 galaxy. We suggest that this object may be typical of the hard sources required to explain the remainder of the X-ray background at hard energies. |
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| Keywords: | galaxies: active galaxies: individual: AXJ0341–4453 quasars: general X-rays: general |
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